Ferroelectric memory which is referred to as FeRAM is conventionally known.
The ferroelectric memory is a memory element with a multilayer structure made of a lower electrode layer, a ferroelectric layer, and an upper electrode layer. The ferroelectric memory is fabricated in the following manner (for example, see Patent Document 1). On a substrate, a foundation layer made from an insulating material is deposited. On the foundation layer, a lower electrode layer made from precious metal such as Pt, a ferroelectric layer made from PZT (Pb(Zr,Ti)O3), and an upper electrode layer made from precious metal such as Pt are sequentially deposited into a multilayer film. The multilayer film is subjected to etching. In the step of etching the multilayer film, for example a plasma processing apparatus using an inductively-coupled plasma is used.
However, in the conventional plasma processing apparatus using an inductively-coupled plasma, when the multilayer film is subjected to etching, a precious metal and a ferroelectric making up the multilayer film is adhered to the dielectric member that introduces high-frequency power into the chamber (vacuum container), to thereby seal the high-frequency power. This leads to a problem in that the plasma becomes unstable. Furthermore, another problem arises in that this adhering matter is exfoliated to increase the particles of the multilayer film.
Therefore, to remove the adhering matter, impacts of ions produced when high-frequency power is applied to an electrostatically-coupled electrode are used (see Patent Document 2).
[Patent Document 1] Japanese Unexamined Patent Application, First Publication No. 2006-344785
[Patent Document 2] Japanese Patent No. 3429391